Instrument pump



OOLQ, 1928. I 1,687,469

- R. w. BROWN INSTRUMENT PUMP File 1925 3 Sheets-Sheet l 2 I N VEN TOR.

fir M Exam,

ATTORNEY.

Oct. 9, 1928. 1,687,469

R. w. BROWN INSTRUMENT PUMP Filed Feb. 20, 1925 3 Sheets-Sheet 2 IN VENTOR.

ATTORNEY.

Oct. 9, 1928.

R. W. BROWN INSTRUMENT PUMP Filed Feb. 20, 1925 3 Sheets-Sheet 5 IN VEN TOR. 1%) W. 5mm.

' ATTORNEY.

Patented (let. 9,1928.

7 1,687,469 UNITED stares PATENT OFFICE.

nor w. BROWN, or AKRON, or-rro, assrenon re Tran rinns'roivn Tran AND RUBBER COMPANY, or AKRON, orrmri cortroaa'rrou or OHIO.

'ENSTBUMEN'I PUMP;

This'invention relates to instrument pumps and particularly. ClQVlCQS lEOl maintaining a uniformly constant flowior constant flows of a I gas or gases or mixtures thereof through a device such as an indicating or recording instrument. The invention .also relates to a method of'pumping fluids. A specificapplication ofthepump as will be describedherein, is for maintaining flows oi gases, one from achamber containing a mixture of gases and the other from asource of onset the 'gases of the mixture through an instrument forindieating or recording the percentage of the aases in the mixture. Itwill beunderstood, l5 however, that the pump of the invention is capable of general application.

In solvent recovery, such as the recovery of benzo'l or other solvent from a mixture with air or an inert or other gas, where the solvent is explosive it is otten desirable to maintain the mixture in the chamber below a certain percentage of-the explosive solvent. In driers such as used for drying fabric or the like which has beenfcoated with rubber by dipping the fabric into a solution of rubber in benzol, the benzol is usually evaporated from the fabric-by heaters in an atmosphere of producer gas orearbondioxide. and in order that the supply of carbon-dioxide to the drier can 30 be governed formaintaining a low percentage of solvent in the atmosphere oit'the chamber, an instrument has heretofore been employed for i ndicatine; the percentage ofthe solvent at all times. This instrument has included. a Wheat-stones bridge having resistance elementstherein over'oneof which the mixture ofsolvent and gas from the chamber is conducted and over the other of which the producer or other in thecondition in which it is fed into the chamber is conducted, the bridge being-so designed and arranged that it isbalanced when the percentage of solvent in the mixture does not exceed the safe maXimum and a galvanometer will indicate that A particular object is to provide a pump functioning on the principle of an aspirator or steam injector and arranged to be automatically controlled to draw a gas at a constant velocity through an instrumentor the like,

I Another object is to provide a pump as described above arranged to maintain a-constant'head of a liquid therein through which head oi liquid the pump will be eiiective to draw the gas or. gases from a chamber or other. source through the instrument or the like the head or liquid being also adapted to provide a telltale or indicator showing that the pump is o icratinp; properly, the pump being housed in a'transparent container for this latter purpose.

The above and other objects of the invention are obtained by the constructlon illustratcd in the accompanying drawings and described in detail below It is to be understood that the invention is not limited to the specific construction shown and described.

Qt the accompanying drawings:

Figure 1 is a front elevation partly in sec tion' of a pump constructed in accordance with the invention;

Figure 2 is a vertical diametrical section on l ne 2-2 of F i gure 1; and

'ure 8 is a plan thereof.

Referring to the drawin s, 10 is preferably a trai'isparent casing ct or other materiah having a top 11 of metal. or otherma terial secured thereon the joint between casing 10 and 'top 11 being sealed to render the casing air-tight as by means of a gasket '12.

A bottom 130i metal or other material is secured onto casing 10 and the joint between casing- 10 and the bottom iscorrespondingly sealed by a gasket let rendering the casing 10 air-tight and water-tight. through casing 10 is an aspirator 15 including members 16 and 1'{', the tormer beingthrea-ded through top 11 and provided with a lateral inlet 18 leadingto its bore 19, the upperend of which is closed by a plug 20. The nozzle oit member 16 isindicated at 21 and it is en- ..circled by member 17, the bore 17 of which is 0f member 16 above the nozzle 21. The bore 17 extends *hroug'h member 17 and is constricted as at 29, adjacent nozzle and gradually becomes larger to ard the bottom of member 17. Member 17 extends through hotill conductors, one of which leads from a chamber containing mixed gases or the and solvent through the instrument for measuring the percentage of gases in the mixture or the percentage of solvent and the other one of which leads from a source of one of the gases through said instrument. Apertures 2? and 28 are respectively, connected by ducts 29 and 30 to bores 31 and 32 in valve body 26, bores 31 and 32, respectively, having tubes 33 and 34 connected thereto and arranged to extend downwardly in casing 10 to adjacent bottom 18, the tubes being reversely bent at their bottom portions to provide upwardly directed outlets and 36. Valve body 26 is secured on top 1 by an extension 26 thereon screw-threadedly received in a threaded aperture 26 in top 11, bores 31 and32 being arranged so as to extend through the extension 26. For controlling the flow through the pump, valves 37, 38 are respectively arranged to operate in ducts 29 and 30, the valves being formed on stems threaded through apertures 39 and 10 in valve body 26 andoperable respectively by knobs 4-1 and i2. To seal apertures 39 and 10, packings 4-3 and 44.- are respectively provided around valve stems 37 and 88 and are held under compression against valve body 26 by screw caps 45 and 16 threaded thereon.

Arranged below bottom 13 is a pan 4'? secured thereon and sealed at the joint with bottom 13 by a gasket AS, the pan 4'? being formed with a trough-shaped outlet 49 under which is arranged a suitable drain pipe 50. The drain outlet 49 is of su'fiicient height above the bottom of pan 17 to maintain a quantity of as liquid therein of such height that the lower end of member 17 will project below the surface thereof and also, so that the liquid will overflow a wall 51 into a compartment 52 in the pan 1'? so as to provide a seal for a pipe or tube 53 connected with the interior of casing 10 by being threaded through an aperture 54 in bottom 13.

The pump may be suitably secured on a wall or the like by means of a bracket 55 suitably secured to the top 11.

In the use of the pump, the conductors or pipes through which the flow of gas or gases are to be pumped are connected to ducts 27.

and 28. Water or other fluid is then supplied through inlet 18 and as it passes through aspirator 15 1t creates asuction through apertures 25 as will be understood. The water 18 discharged into pan l? in which it rises to the level shown, surplus water flowing into dra n 50. As soon as the lower end or" tube 53 is sealed the suction through apertures 25 is effective-to draw water from pan 47 up through tube 53 into casinglO in which it rises to the height of openings 25 and then redischarges through member 1'? into the pan. The aspirator maintains this level the water circulating'through member 17, pan 47. tube 53 and casing 10 to the level indicated and then through ducts 25, etc. Surplus water continuously passes out drain outlet 19 into drain 50.'

The suction created by aspirator 15 under the above described conditions will now tend to evacuate the space in casing 10 above ducts 25 andwill draw the mixed solvent and gas and the pure gas through the instrument system through the valves 37 and 38, through the tubes 33and 3 1 into thecasing 10 against the constant head of water therein, the gases bubblingthrough the water (Figure 1) into the space thereabove in casing lO'irom which they will continuously be exhausted by the aspirator 15. Valves 37 and 38 are adjusted to secure the desired flow and to provide for the same'rate of flow of both the mixture of solvent and gas and the pure gas;

Due to the constant'headof liquid maintained in casing 10 against which the gases are drawn through the pump and due to the fact that variation in the velocity of water through the aspiratorwill' be effective only to vary the rapidity of circulation of the water without varying the suction effective above the level of the water, the velocity at which the gas or gases will be pumped through a system will be uniformly constant.

Modifications of the invention may beresorted to without departing from the spirit thereof or the scope of the appended claims.

' What is claimedis:

1. A constant flow pump comprising a vessel having a fluid inlet therein and means for evacuating the vessel, said evacuating means being adapted to maintain a constant head of a liquid in the vessel above said inlet.

2. A constant flow pump comprising a vessel having a fluid inlet therein and means for evacuating the vessel, said evac-uatingmeans being adapted to maintain a constant head of a liquid in the vessel above said inlet and above said inlet with the liquid discharged from the aspirator.

5. A constant flow pump comprising a. vessel, an aspirator extending through the vessel, means for supplying a liquid to the aspirator, means for receiving liquid from the as pirator, said aspirator tending to evacuate the vessel as the liquid passes th'crethrough, and means extending from the rece1v1ng means into the vessel for conducting the l1qu1d thereinto, said aspirator being adapted to draiv said liquid up from the receiving means to a constant level in the vessel, and means for discharging a fluid from a fluid-conducting system at a point below said level of liquid.

6. A pump for producing uniform flows of gases through a plurality of systems, said pump comprising a vessel having an outlet at the same level therein from each such system,

and means for creating a vacuum in said vessel and adapted to provide a constant head of a liquid above said outlets.

7. A pump comprising a closed vessel, an aspirator Xtending through the vessel and tending to maintain a vacuum therein, means for furnishing a liquid to the aspirator, and means for discharging the liquid from the aspirator, said last means being adapted to provide a supply of liquid to be drawn into the vessel by the aspirator,

8. An instrument pump comprising a closed vessel, an aspirator operable in the vessel, means for supplying a liquid to the aspirator,

said aspirator discharging outside thevessel,

and means whereby said aspirator will be effective to draw a portion of the liquid discharged therefrom up into the vessel to a constant level. i a p 9. An instrument pump comprising a closed vessel, an aspirator operable in thevessel,

means for supplying a liquid to the aspirator,

' said aspirator discharging outside the vessel,

and'means whereby said aspirator will be effective to draw a portion of the l1qu1d discharged therefrom up into the vessel to a constant level, and to recirculate said water with its discharge.

10. An instrument pump comprising a closed vessel, an aspirator extending through the vessel and operable therein, means outside the vessel for supplying a liquid to the aspirator, a pan outside of the vessel for receiving the liquid therefrom, said pan having a discharge outlet therefrom so arranged as to provide for maintainin a uantit of the lit uid in said pan, and liquid conducting means connected to the interior of the vessel and extend ing into the liquid in the pan.

11. An instrument pump comprising a closed vessel having an outlet from a fluid conducting system therein, an aspirator eX- tending through the vessel and operable therein, means for supplying a liquid to the aspirator, a pan for receiving the liquid from the aspirator and adapted to maintain a supply of liquid therein, and a liquid conductor extending into the supply of liquid in the pan and leading into the interior of the vessel whereby said aspirator will be efl ective to provide a constant head of the liquid in the vessel above said outlet.

- ROY W. BRO'WN. 

